This invention relates in general to lock sets and more particularly relates to the addition of a hotel function to a lock set without materially increasing the cost of manufacturing the lock set.
It is known that lock sets have different functions which require the lock sets to operate in slightly different ways for each specific function. For example, the typical lock set used on an entry door controlling egress and ingress into a building may be placed in either locked or merely latched modes of operation. When such a lock is in its latched mode, either the inside or outside hand operator, typically a knob or lever, may be turned to retract the latch bolt.
The identical lock set cannot generally be used to perform a hotel function. When a lock set is used on the door of a hotel room or the like, the outside or exterior hand operator is generally maintained in a fixed position; i.e., prevented from rotating relative to the door. This feature increases the security of the room since, even when the inside hand operator is unlocked, only a person with a key can gain access from the exterior of the room, since movement of the latch bolt is solely responsive to rotation of the plug of the lock cylinder.
In some instances, it may be desirable to change the lock cylinder so that entry into the hotel room may only be gained by someone having a key to fit a new cylinder. Changing the cylinder is commonly referred to as "rekeying". Any person only having a key fitting the removed cylinder, will not be able to gain entry into the hotel room. In some lock sets, the outside hand operator must be removed before the lock cylinder can be removed for replacement thereof. Removal of the hand operator often necessitates its rotation; as indicated previously the rotation of the outside hand operator is prevented in lock sets performing a hotel or similar function.
Very often, in order to convert a standard lock set used on an entry door to a building or room, to a lock set suitable for use in a hotel application, significant changes must be made. By making significant changes to the design of a lock set, the number of interchangeable parts between a standard lock set and a hotel lock set is reduced and the manufacturing costs and inventory costs of each of the lock sets are increased.
Accordingly, it is an object of this invention to convert a standard lock set to a lock set suitable for use in a hotel function by implementing a minimal number of changes to parts of the standard lock set.